Metabolism and Cellular Respiration

ATP (Adenosine Triphosphate): The main energy carrier in biological systems that stores and releases energy as needed by the cell.

Cellular Respiration: A metabolic pathway that transforms food molecules into ATP to provide energy for cellular functions.

Citric Acid Cycle (Krebs Cycle): The second step of cellular respiration that occurs in the mitochondrial matrix, processing Acetyl CoA to produce electron carriers and carbon dioxide.

Electron Carriers: Molecules like NAD and FAD that transport electrons during cellular respiration, facilitating ATP generation.

Glycolysis: The initial stage of cellular respiration occurring in the cytoplasm, which breaks down glucose into two pyruvate molecules.

Metabolism: The collection of chemical processes in living organisms that maintain life, including the conversion of food into usable energy.

Metabolic Pathway: A series of enzymatic reactions that lead to the conversion of a substrate into a final product.

Oxidative Phosphorylation: The final stage of cellular respiration where ATP is produced via the electron transport chain in the mitochondrial inner membrane.

Photosynthesis: The process by which organisms, such as plants, convert light energy into chemical energy through metabolic pathways, generating glucose and oxygen.

Redox Reactions: Reactions that involve the transfer of electrons between substances, encompassing oxidation (loss of electrons) and reduction (gain of electrons).

Metabolism consists of all chemical processes that sustain life, including molecule transport and energy conversion.

Metabolic pathways systematically convert substrates into products through interconnected biochemical reactions.

Cellular respiration is essential for converting food into ATP and operates in three main steps: Glycolysis, Citric Acid Cycle, and Oxidative Phosphorylation.

Glycolysis occurs in the cytoplasm, splitting glucose into two pyruvate molecules.

The Citric Acid Cycle takes place in the mitochondrial matrix, producing energy carriers and carbon dioxide.

Oxidative Phosphorylation is the final step, generating the majority of ATP in the mitochondria through the electron transport chain.

ATP is generated from biological molecules through metabolic pathways.

The conversion of ATP to ADP involves losing a phosphate group and releasing energy.

Oxidative phosphorylation can yield between 32 to 34 ATP molecules.

Byproducts of cellular respiration include carbon dioxide and water.

ATP yield can be influenced by hydrogen ion pumping capacity in the electron transport chain, the type of electron carriers used, variations in tissue types, and the use of intermediate products in other pathways.

Overall equation for Cellular Respiration:

Glycolysis Inputs and Outputs:

Input: 1 glucose, 2 ATP

Output: 2 pyruvates, 2 ATP (net), 2 NADH

Outputs of the Citric Acid Cycle:

Produces: 2 Acetyl CoA, 2 NADH, and 2 CO2.

Glycolysis: Crucial for anaerobic organisms, allowing energy production without oxygen.

Cellular Respiration Steps:

Glycolysis,

Citric Acid Cycle (Krebs Cycle),

Oxidative Phosphorylation.

ATP Synthase: The enzyme responsible for synthesizing ATP from ADP and inorganic phosphate during oxidative phosphorylation.